Use of Low-Flow Flowmeter to Titrate the FiO2 Delivered in Neonatal Resuscitation

Introduction: The oxygen concentration used in neonatal resuscitation has been a matter of debate with higher oxygen concentrations posing many adverse outcomes. Recent guidelines recommend use of blender to titrate FiO2 delivered during resuscitation. However, blender being unaffordable and unavailable at many peripheral institutions, we tried to use a low-flow flowmeter to titrate the oxygen and measure FiO2 delivered at different flow rates. Methods: From a central oxygen supply, oxygen flow was titrated using a low-flow flowmeter which was connected to a self-inflating bag and oximeter. Three variables were taken—volume of self-inflating bag, flow rate, and number of compressions per minute. FiO2 delivered with each variable, keeping the other two constant, was recorded. Results: The data obtained was analyzed by fitting the study variables into a stepwise multiple linear regression model and a linear equation was obtained. The model R square obtained suggested strong linear relationship between flow rate and FiO2 delivered. The model showed statistically significant association between flow rate and FiO2 delivery, whereas association with other variables was statistically insignificant. Discussion: Our study suggests that 76.57% of change in FiO2 is determined by change in flow rate. The major advantage of this study would be at resource poor settings where a low-flow flowmeter which is more cost effective can be used to titrate the FiO2 delivered during neonatal resuscitation.

Comparative Structural Study of Three Tetrahalophthalic Anhydrides: Recognition of X···O(anhydride) Halogen Bond and πh···O(anhydride) Interaction

Structures of three tetrahalophthalic anhydrides (TXPA: halogen = Cl (TCPA), Br (TBPA), I (TIPA)) were studied by X-ray diffraction, and several types of halogen bonds (HaB) and lone pair···π-hole (lp···πh) contacts were revealed in their structures. HaBs involving the central oxygen atom of anhydride group (further X···O(anhydride) were recognized in the structures of TCPA and TBPA. In contrast, for the O(anhydride) atom of TIPA, only interactions with the π system (π-hole) of the anhydride ring (further lp(O)···πh) were observed. Computational studies by a number of theoretical methods (molecular electrostatic potentials, the quantum theory of atoms in molecules, the independent gradient model, natural bond orbital analyses, the electron density difference, and symmetry-adapted perturbation theory) demonstrated that the X···O(anhydride) contacts in TCPA and TBPA and lp(O)···πh in TIPA are caused by the packing effect. The supramolecular architecture of isostructural TCPA and TBPA was mainly affected by X···O(acyl) and X···X HaBs, and, for TIPA, the main contribution provided I···I HaBs.

Baseline characteristics, level of disease severity and outcomes of patients with COVID-19 admitted to intensive care unit in COVID-19 dedicated Mugda Medical College and Hospital, Dhaka, Bangladesh

Background: Novel coronavirus disease is associated with highly intensive care unit (ICU) mortality. With the dramatic increase of confirmed cases as well as death toll in Bangladesh, timely and effective management of severely and critically ill patients appears to be particularly important. This includes streamlining workflows for rapid diagnosis and isolation, clinical management, and infection prevention. The main objective of this study was identification of the demographic, clinical characteristics, severity and outcome of patients admitted into ICU. Methods: We aimed to describe the demographic and clinical characteristics, severity of disease, management patterns and outcomes of critically ill patients with coronavirus disease 2019 admitted to ICU in a Bangladeshi setting and for this purpose a retro-prospective study of conveniently selected 63 ICU admitted patients with COVID-19 was conducted from May 1 to June 30, 2020. Data were obtained from patient charts and the hospitals’ records using a structured questionnaire. Results: Most of the ICU patients were older male (30, 65.3%) and most of them were 70 or above years of age group (17, 37.0%). ICU patients more likely suffered from comorbidities like hypertension (938, 60.3%); diabetes (36, 57.1%); chronic kidney disease (21, 33.3%). In most cases treatment in ICU included the administration of antibiotics (100.0%) (Meropenem, 20, 31.7%). Forty-Eight patients died (discharge mortality, 76.2%), and fourteen patients were discharged alive from the ICU with a rate of 22.2%. One patient transferred (Palliative discharge, 1.6%) to other facilities for palliative care purpose.Conclusions: Our findings also highlight the importance of planning for mass critical care along with central oxygen supply system as the need for ICU care and ventilator support to treat patients with COVID-19 grows rapidly in Bangladesh.

Properties of galaxies with an offset between the position angles of the major kinematic and photometric axes

We derive the photometric, kinematic, and abundance characteristics of 18 star-forming MaNGA galaxies with fairly regular velocity fields and surface brightness distributions and with a large offset between the measured position angles of the major kinematic and photometric axes, ΔPA ≳ 20°. The aim is to examine if there is any other distinctive characteristic common to these galaxies. We found morphological signs of interaction in some (in 11 out of 18) but not in all galaxies. The observed velocity fields show a large variety; the maps of the isovelocities vary from an hourglass-like appearance to a set of straight lines. The position angles of the major kinematic axes of the stellar and gas rotations are close to each other. The values of the central oxygen abundance, radial abundance gradient, and star formation rate are distributed within the intervals defined by galaxies with small (no) ΔPA of similar mass. Thus, we do not find any specific characteristic common to all galaxies with large ΔPA. Instead, the properties of these galaxies are similar to those of galaxies with small (no) ΔPA. This suggests that either the reason responsible for the large ΔPA does not influence other characteristics or the galaxies with large ΔPA do not share a common origin, they can, instead, originate through different channels.

Bis{4-[(2-hydroxy-5-methoxy-3-nitrobenzylidene)amino]phenyl} ether

The molecule of the title compound, C28H22N4O9, exhibits crystallographically imposed twofold rotational symmetry, with a dihedral angle of 66.0 (2)° between the planes of the two central benzene rings bounded to the central oxygen atom. The dihedral angle between the planes of the central benzene ring and the terminal phenol ring is 4.9 (2)°. Each half of the molecule exhibits an imine E configuration. An intramolecular O—H...N hydrogen bond is present. In the crystal, the molecules are linked into layers parallel to the ab plane via C—H...O hydrogen bonds. The crystal studied was refined as a two-component pseudomerohedral twin.

Lateral Acquisitions Repeatedly Remodel the Oxygen Detoxification Pathway in Diplomonads and Relatives

Oxygen and reactive oxygen species (ROS) are important stress factors for cells because they can oxidize many large molecules. Fornicata, a group of flagellated protists that includes diplomonads, have anaerobic metabolism but are still able to tolerate fluctuating levels of oxygen. We identified 25 protein families putatively involved in detoxification of oxygen and ROS in this group using a bioinformatics approach and propose how these interact in an oxygen detoxification pathway. These protein families were divided into a central oxygen detoxification pathway and accessory pathways for the synthesis of nonprotein thiols. We then used a phylogenetic approach to investigate the evolutionary origin of the components of this putative pathway in Diplomonadida and other Fornicata species. Our analyses suggested that the diplomonad ancestor was adapted to low-oxygen levels, was able to reduce O2 to H2O in a manner similar to extant diplomonads, and was able to synthesize glutathione and l-cysteine. Several genes involved in the pathway have complex evolutionary histories and have apparently been repeatedly acquired through lateral gene transfer and subsequently lost. At least seven genes were acquired independently in different Fornicata lineages, leading to evolutionary convergences. It is likely that acquiring these oxygen detoxification proteins helped anaerobic organisms (like the parasitic Giardia intestinalis) adapt to low-oxygen environments (such as the digestive tract of aerobic hosts).

Improved seismic model of the pulsating DB white dwarf KIC 08626021 corrected from the effects of neutrino cooling

Asteroseismology is a powerful tool to unravel the chemical composition and stratification inside white dwarfs, as recently achieved by Giammichele et al. (2018, Nature, 554, 73) for the pulsating DB star KIC 08626021. However, Timmes et al. (2018, ApJ, 867, L30) pointed out that neglecting the effects of neutrino cooling, such as in the models used in Giammichele et al. study, could significantly impact the derived seismic solution and compromise conclusions drawn upon it. In this context, we perform a complete reevaluation of the seismic solution uncovered for KIC 08626021, using improved static models which incorporate more realistic luminosity profiles that reflect the still significant energy losses induced by neutrino emission mechanisms in hot DB white dwarfs. We find that including (or neglecting) neutrino cooling for the specific case of KIC 08626021 induces frequency differences of ∼35 μHz on average (with variations up to ∼84 μHz) for the relevant g-modes, that is, similar to the frequency shifts estimated in Timmes et al. study. However, we show that the propagation of these variations into the derived seismic model properties remain limited and mainly trigger changes of the C/O and C/He composition ratio in the intermediate layers of the seismic model, while other important parameters are only slightly affected. In particular, the derived central oxygen mass fraction and extent of the homogeneous inner part of the core are essentially unchanged. Hence, as found by Timmes et al., seismic investigations of hot pulsating DB white dwarfs that rely on parameterized static models should include the non-negligible effects of neutrino cooling to provide more accurate solutions, but all the important conclusions brought by Giammichele et al. from the analysis of KIC 08626021 remain entirely valid.